/*
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * Kamailio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version
 *
 * Kamailio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

/*! \file
 * \brief Parser :: ???
 *
 * \ingroup parser
 */


#ifndef msg_parser_h
#define msg_parser_h


#include "../comp_defs.h"
#include "../str.h"
#include "../lump_struct.h"
#include "../flags.h"
#include "../ip_addr.h"
#include "../config.h"
#include "parse_def.h"
#include "parse_cseq.h"
#include "parse_via.h"
#include "parse_fline.h"
#include "parse_retry_after.h"
#include "hf.h"
#include "../error.h"


/*! \name convenience short-cut macros */
/*@{ */
#define REQ_LINE(_msg) ((_msg)->first_line.u.request)
#define REQ_METHOD first_line.u.request.method_value
#define REPLY_STATUS first_line.u.reply.statuscode
#define REPLY_CLASS(_reply) ((_reply)->REPLY_STATUS / 100)
/*@} */

/*! \brief start of "actual" sip msg (start of first line) */
#define SIP_MSG_START(m) ((m)->first_line.u.request.method.s)

/*! \brief number methods as power of two to allow bitmap matching */
typedef enum request_method
{
	METHOD_UNDEF = 0,		/*!< 0 - --- */
	METHOD_INVITE = 1,		/*!< 1 - 2^0 */
	METHOD_CANCEL = 2,		/*!< 2 - 2^1 */
	METHOD_ACK = 4,			/*!< 4 - 2^2 */
	METHOD_BYE = 8,			/*!< 8 - 2^3 */
	METHOD_INFO = 16,		/*!< 16 - 2^4 */
	METHOD_REGISTER = 32,	/*!< 32 - 2^5 */
	METHOD_SUBSCRIBE = 64,	/*!< 64 - 2^6 */
	METHOD_NOTIFY = 128,	/*!< 128 - 2^7 */
	METHOD_MESSAGE = 256,	/*!< 256 - 2^8 */
	METHOD_OPTIONS = 512,	/*!< 512 - 2^9 */
	METHOD_PRACK = 1024,	/*!< 1024 - 2^10 */
	METHOD_UPDATE = 2048,	/*!< 2048 - 2^11 */
	METHOD_REFER = 4096,	/*!< 4096 - 2^12 */
	METHOD_PUBLISH = 8192,	/*!< 8192 - 2^13 */
	METHOD_KDMQ = 16384,	/*!< 16384 - 2^14 */
	METHOD_GET = 32768,		/*!< 32768 - 2^15 */
	METHOD_POST = 65536,	/*!< 65536 - 2^16 */
	METHOD_PUT = 131072,	/*!< 131072 - 2^17 */
	METHOD_DELETE = 262144, /*!< 262144 - 2^18 */
	METHOD_OTHER = 524288	/*!< 524288 - 2^19 */
} request_method_t;

#define FL_FORCE_RPORT (1ULL << 0)	/*!< force rport */
#define FL_FORCE_ACTIVE (1ULL << 1) /*!< force active SDP */
#define FL_SDP_IP_AFS (1ULL << 2)	/*!< SDP IP rewritten */
#define FL_SDP_PORT_AFS (1ULL << 3) /*!< SDP port rewritten */
#define FL_SHM_CLONE (1ULL << 4)	/*!< msg cloned in SHM as a single chunk */
#define FL_TIMEOUT \
	(1ULL << 5) /*!< message belongs to an "expired" branch
									(for failure route use) */
#define FL_REPLIED \
	(1ULL << 6) /*!< message branch received at least one reply
									(for failure route use) */
#define FL_HASH_INDEX \
	(1ULL << 7) /*!< msg->hash_index contains a valid value (tm use)*/

#define FL_MTU_TCP_FB (1ULL << 8)
#define FL_MTU_TLS_FB (1ULL << 9)
#define FL_MTU_SCTP_FB (1ULL << 10)
#define FL_ADD_LOCAL_RPORT (1ULL << 11) /*!< add 'rport' to local via hdr */
#define FL_SDP_BODY (1ULL << 12)		/*!< msg has SDP in body */
#define FL_USE_UAC_FROM (1ULL << 13) /* take FROM hdr from UAC instead of UAS*/
#define FL_USE_UAC_TO (1ULL << 14)	 /* take TO hdr from UAC instead of UAS */
#define FL_TM_RPL_MATCHED (1ULL << 15) /* tm matched reply already */
#define FL_RPL_SUSPENDED (1ULL << 16)  /* for async reply processing */
#define FL_BODY_MULTIPART (1ULL << 17) /* body modified is multipart */
#define FL_RR_ADDED (1ULL << 18)	   /* Record-Route header was added */
#define FL_UAC_AUTH (1ULL << 19)	   /* Proxy UAC-like authentication */
#define FL_ADD_SRVID (1ULL << 20)	   /*!< add 'srvid' to local via hdr */
#define FL_ADD_XAVP_VIA_PARAMS \
	(1ULL << 21) /*!< add xavp fields to local via params */
#define FL_USE_XAVP_VIA_FIELDS \
	(1ULL << 22)					/*!< use xavp fields for local via attrs */
#define FL_MSG_NOREPLY (1ULL << 23) /*!< do not send sip reply for request */
#define FL_SIPTRACE \
	(1ULL << 24) /*!< message to be traced in stateless replies */
#define FL_ROUTE_ADDR \
	(1ULL << 25) /*!< request has Route address for next hop */
#define FL_USE_OTCPID \
	(1ULL << 26) /*!< request to be routed using outbound tcp con id */
#define FL_ADD_XAVP_VIA_REPLY_PARAMS \
	(1ULL << 27) /*!< add xavp fields to first (previous sip node) via params */

/* WARNING: Value (1 << 28) is reserved for use in kamailio call_control
 * module (flag  FL_USE_CALL_CONTROL )! */

/* WARNING: Value (1 << 29) is reserved for use in kamailio acc
 * module (flag FL_REQ_UPSTREAM)! */

/* WARNING: Value (1 << 30) is reserved for use in kamailio
 * media proxy module (flag FL_USE_MEDIA_PROXY)! */

/* WARNING: Value (1 << 31) is reserved for use in kamailio
 * nat_traversal module (flag FL_DO_KEEPALIVE)! */

#define FL_FINAL_REPLY (1ULL << 32)	   /* local final reply sent */
#define FL_DELAYED_REPLY (1ULL << 33)  /* local reply sending delayed */
#define FL_VIA_NORECEIVED (1ULL << 34) /* no received test for incoming Via */

#define FL_MTU_FB_MASK (FL_MTU_TCP_FB | FL_MTU_TLS_FB | FL_MTU_SCTP_FB)


/* sip parser mode flags (1<<n) */
#define KSR_SIP_PARSER_MODE_NONE 0
#define KSR_SIP_PARSER_MODE_STRICT 1

#define IFISMETHOD(methodname, firstchar)                                  \
	if((*tmp == (firstchar) || *tmp == ((firstchar) | 32))                 \
			&& strncasecmp(tmp + 1, &#methodname[1], methodname##_LEN - 1) \
					   == 0                                                \
			&& *(tmp + methodname##_LEN) == ' ') {                         \
		fl->type = SIP_REQUEST;                                            \
		fl->u.request.method.len = methodname##_LEN;                       \
		fl->u.request.method_value = METHOD_##methodname;                  \
		tmp = buffer + methodname##_LEN;                                   \
	}


/* sip request */
#define IS_SIP(req)                          \
	(((req)->first_line.type == SIP_REQUEST) \
			&& ((req)->first_line.flags & FLINE_FLAG_PROTO_SIP))

/* sip request */
#define IS_SIP_REQUEST(req)                  \
	(((req)->first_line.type == SIP_REQUEST) \
			&& ((req)->first_line.flags & FLINE_FLAG_PROTO_SIP))

/* sip reply */
#define IS_SIP_REPLY(rpl)                  \
	(((rpl)->first_line.type == SIP_REPLY) \
			&& ((rpl)->first_line.flags & FLINE_FLAG_PROTO_SIP))

/* sip message */
#define IS_SIP_MSG(req) ((req)->first_line.flags & FLINE_FLAG_PROTO_SIP)

/* http request */
#define IS_HTTP(req)                         \
	(((req)->first_line.type == SIP_REQUEST) \
			&& ((req)->first_line.flags & FLINE_FLAG_PROTO_HTTP))

/* http reply */
#define IS_HTTP_REPLY(rpl)                 \
	(((rpl)->first_line.type == SIP_REPLY) \
			&& ((rpl)->first_line.flags & FLINE_FLAG_PROTO_HTTP))

/*! \brief
 * Return a URI to which the message should be really sent (not what should
 * be in the Request URI. The following fields are tried in this order:
 * 1) dst_uri
 * 2) new_uri
 * 3) first_line.u.request.uri
 */
#define GET_NEXT_HOP(m)                                     \
	(((m)->dst_uri.s && (m)->dst_uri.len)                   \
					? (&(m)->dst_uri)                       \
					: (((m)->new_uri.s && (m)->new_uri.len) \
									? (&(m)->new_uri)       \
									: (&(m)->first_line.u.request.uri)))


/*! \brief
 * Return the Reqeust URI of a message.
 * The following fields are tried in this order:
 * 1) new_uri
 * 2) first_line.u.request.uri
 */
#define GET_RURI(m)                                         \
	(((m)->new_uri.s && (m)->new_uri.len) ? (&(m)->new_uri) \
										  : (&(m)->first_line.u.request.uri))


/*! \brief
 * Return the SIP port.
 * - _port if _port!=0
 * - 5061 for _proto == TLS or WSS
 * - 5060 for the other _proto
 */
#define GET_SIP_PORT(_port, _proto)                                      \
	((_port == 0) ? (                                                    \
			 (_proto == PROTO_TLS || _proto == PROTO_WSS) ? 5061 : 5060) \
				  : _port)

enum _uri_type
{
	ERROR_URI_T = 0,
	SIP_URI_T,
	SIPS_URI_T,
	TEL_URI_T,
	TELS_URI_T,
	URN_URI_T
};
typedef enum _uri_type uri_type;
enum _uri_flags
{
	URI_USER_NORMALIZE = 1,
	URI_SIP_USER_PHONE = 2
}; /* bit fields */
typedef enum _uri_flags uri_flags;

typedef unsigned long long msg_flags_t;

/*! \brief The SIP uri object */
struct sip_uri
{
	str user;		/*!< Username */
	str passwd;		/*!< Password */
	str host;		/*!< Host name */
	str port;		/*!< Port number */
	str params;		/*!< Parameters */
	str sip_params; /*!< Parameters of the sip: URI.
					* (If a tel: URI is embedded in a sip: URI, then
					* params points to the parameters of the tel: URI,
					* and sip_params to the parameters of the sip: URI.
					*/
	str headers;
	unsigned short port_no;
	unsigned short proto; /*!< from transport */
	uri_type type;		  /*!< uri scheme */
	uri_flags flags;
	/*!< parameters */
	str transport;
	str ttl;
	str user_param;
	str maddr;
	str method;
	str lr;
	str r2; /*!< ser specific rr parameter */
	str gr;
	str transport_val;	/*!< transport value */
	str ttl_val;		/*!< TTL value */
	str user_param_val; /*!< User= param value */
	str maddr_val;		/*!< Maddr= param value */
	str method_val;		/*!< Method value */
	str lr_val;			/*!< lr value placeholder for lr=on a.s.o*/
	str r2_val;
	str gr_val;
#ifdef USE_COMP
	unsigned short comp;
#endif
};

typedef struct sip_uri sip_uri_t;

struct msg_body;

typedef void (*free_msg_body_f)(struct msg_body **ptr);

typedef enum msg_body_type
{
	MSG_BODY_UNKNOWN = 0,
	MSG_BODY_SDP
} msg_body_type_t;

/*! \brief This structure represents a generic SIP message body, regardless of the
 * body type.
 *
 * Body parsers are supposed to cast this structure to some other
 * body-type specific structure, but the body type specific structure must
 * retain msg_body_type variable and a pointer to the free function as the
 * first two variables within the structure.
 */
typedef struct msg_body
{
	msg_body_type_t type;
	free_msg_body_f free;
} msg_body_t;


/* pre-declaration, to include sys/time.h in .c */
struct timeval;

/* structure for cached decoded flow for outbound */
typedef struct ocd_flow
{
	int decoded;
	struct receive_info rcv;
} ocd_flow_t;

/* structure holding fields that don't have to be cloned in shm
 * - its content is memset'ed to in shm clone
 * - add to msg_ldata_reset() if a field uses dynamic memory */
typedef struct msg_ldata
{
	ocd_flow_t flow;
	void *vdata;
} msg_ldata_t;

/*! \brief The SIP message */
typedef struct sip_msg
{
	unsigned int id;			   /*!< message id, unique/process*/
	int pid;					   /*!< process id */
	struct timeval tval;		   /*!< time value associated to message */
	snd_flags_t fwd_send_flags;	   /*!< send flags for forwarding */
	snd_flags_t rpl_send_flags;	   /*!< send flags for replies */
	struct msg_start first_line;   /*!< Message first line */
	struct via_body *via1;		   /*!< The first via */
	struct via_body *via2;		   /*!< The second via */
	struct hdr_field *headers;	   /*!< All the parsed headers*/
	struct hdr_field *last_header; /*!< Pointer to the last parsed header*/
	hdr_flags_t parsed_flag;	   /*!< Already parsed header field types */

	/* Via, To, CSeq, Call-Id, From, end of header*/
	/* pointers to the first occurrences of these headers;
	 * everything is also saved in 'headers'
	 * (WARNING: do not deallocate them twice!)*/

	struct hdr_field *h_via1;
	struct hdr_field *h_via2;
	struct hdr_field *callid;
	struct hdr_field *to;
	struct hdr_field *cseq;
	struct hdr_field *from;
	struct hdr_field *contact;
	struct hdr_field *maxforwards;
	struct hdr_field *route;
	struct hdr_field *record_route;
	struct hdr_field *content_type;
	struct hdr_field *content_length;
	struct hdr_field *authorization;
	struct hdr_field *expires;
	struct hdr_field *proxy_auth;
	struct hdr_field *supported;
	struct hdr_field *require;
	struct hdr_field *proxy_require;
	struct hdr_field *unsupported;
	struct hdr_field *allow;
	struct hdr_field *event;
	struct hdr_field *accept;
	struct hdr_field *accept_language;
	struct hdr_field *organization;
	struct hdr_field *priority;
	struct hdr_field *subject;
	struct hdr_field *user_agent;
	struct hdr_field *server;
	struct hdr_field *content_disposition;
	struct hdr_field *diversion;
	struct hdr_field *rpid;
	struct hdr_field *refer_to;
	struct hdr_field *session_expires;
	struct hdr_field *min_se;
	struct hdr_field *sipifmatch;
	struct hdr_field *subscription_state;
	struct hdr_field *date;
	struct hdr_field *identity;
	struct hdr_field *identity_info;
	struct hdr_field *pai;
	struct hdr_field *ppi;
	struct hdr_field *path;
	struct hdr_field *privacy;
	struct hdr_field *min_expires;

	struct msg_body *body;

	char *eoh;		/*!< pointer to the end of header (if found) or null */
	char *unparsed; /*!< here we stopped parsing*/

	struct receive_info rcv; /*!< source & dest ip, ports, proto a.s.o*/

	char *buf;		  /*!< scratch pad, holds a modified message,
						*  via, etc. point into it */
	unsigned int len; /*!< message len (orig) */

	/* modifications */

	str new_uri; /*!< changed first line uri, when you change this
					don't forget to set parsed_uri_ok to 0*/

	str dst_uri; /*!< Destination URI, must be forwarded to this URI if len != 0 */

	/* current uri */
	int parsed_uri_ok; /*!< 1 if parsed_uri is valid, 0 if not, set if to 0
						if you modify the uri (e.g change new_uri)*/
	struct sip_uri parsed_uri; /*!< speed-up > keep here the parsed uri*/
	int parsed_orig_ruri_ok; /*!< 1 if parsed_orig_uri is valid, 0 if not, set if to 0
								if you modify the uri (e.g change new_uri)*/
	struct sip_uri
			parsed_orig_ruri; /*!< speed-up > keep here the parsed orig uri*/

	struct lump *add_rm;	 /*!< used for all the forwarded requests/replies */
	struct lump *body_lumps; /*!< Lumps that update Content-Length */
	struct lump_rpl *reply_lump; /*!< only for locally generated replies !!!*/

	/*! \brief str add_to_branch;
		whatever whoever want to append to Via branch comes here */
	char add_to_branch_s[MAX_BRANCH_PARAM_LEN];
	int add_to_branch_len;

	unsigned int hash_index;		/*!< index to TM hash table; stored in core
								to avoid unnecessary calculations */
	msg_flags_t msg_flags;			/*!< internal flags used by core */
	flag_t flags;					/*!< config flags */
	flag_t xflags[KSR_XFLAGS_SIZE]; /*!< config extended flags */
	str set_global_address;
	str set_global_port;
	struct socket_info *force_send_socket; /*!< force sending on this socket */
	str path_vec;
	str instance;
	unsigned int reg_id;
	str ruid;
	str location_ua;
	int otcpid; /*!< outbound tcp connection id, if known */

	/* structure with fields that are needed for local processing
	 * - not cloned to shm, reset to 0 in the clone */
	msg_ldata_t ldv;

	/* IMPORTANT: when adding new fields in this structure (sip_msg_t),
	 * be sure it is freed in free_sip_msg() and it is cloned or reset
	 * to shm structure for transaction - see sip_msg_clone.c. In tm
	 * module, take care of these fields for faked environemt used for
	 * runing failure handlers - see modules/tm/t_reply.c */
} sip_msg_t;

/*! \brief pointer to a faked message which was never received ;
	(when this message is "relayed", it is generated out
	of the original request)
*/
#define FAKED_REPLY ((struct sip_msg *)-1)

extern int via_cnt;
/** global  request flags.
 *  msg->msg_flags should be OR'ed with it before
 * a flag value is checked, e.g.:
 * if ((msg->msg_flags|global_req_flags) & FL_XXX) ...
 */
extern msg_flags_t global_req_flags;


int parse_msg(
		char *const buf, const unsigned int len, struct sip_msg *const msg);

int parse_headers(
		struct sip_msg *const msg, const hdr_flags_t flags, const int next);

char *get_hdr_field(
		char *const buf, char *const end, struct hdr_field *const hdr);

void free_sip_msg(struct sip_msg *const msg);

/*! \brief make sure all HFs needed for transaction identification have been
	parsed; return 0 if those HFs can't be found
*/
int check_transaction_quadruple(sip_msg_t *const msg);

/*! \brief returns a pointer to the beginning of the msg's body
 */
char *get_body(sip_msg_t *const msg);

/*! \brief If the new_uri is set, then reset it */
void reset_new_uri(struct sip_msg *const msg);

/*! \brief
 * Make a private copy of the string and assign it to dst_uri
 */
int set_dst_uri(struct sip_msg *const msg, const str *const uri);

/*! \brief If the dst_uri is set to an URI then reset it */
void reset_dst_uri(struct sip_msg *const msg);

hdr_field_t *get_hdr(const sip_msg_t *const msg, const enum _hdr_types_t ht);
hdr_field_t *next_sibling_hdr(const hdr_field_t *const hf);
/** not used yet */
hdr_field_t *get_hdr_by_name(
		const sip_msg_t *const msg, const char *const name, const int name_len);
hdr_field_t *next_sibling_hdr_by_name(const hdr_field_t *const hf);

int set_path_vector(struct sip_msg *msg, str *path);

void reset_path_vector(struct sip_msg *const msg);

int set_instance(struct sip_msg *msg, str *instance);

void reset_instance(struct sip_msg *const msg);

int set_ruid(struct sip_msg *msg, str *ruid);

void reset_ruid(struct sip_msg *const msg);

int set_ua(struct sip_msg *msg, str *location_ua);

void reset_ua(struct sip_msg *const msg);

/** force a specific send socket for forwarding a request.
 * @param msg - sip msg.
 * @param fsocket - forced socket, pointer to struct socket_info, can be 0 (in
 *                  which case it's equivalent to reset_force_socket()).
 */
#define set_force_socket(msg, fsocket)                      \
	do {                                                    \
		(msg)->force_send_socket = (fsocket);               \
		if((msg)->force_send_socket)                        \
			(msg)->fwd_send_flags.f |= SND_F_FORCE_SOCKET;  \
		else                                                \
			(msg)->fwd_send_flags.f &= ~SND_F_FORCE_SOCKET; \
	} while(0)

/** reset a previously forced send socket. */
#define reset_force_socket(msg) set_force_socket(msg, 0)

/**
 * struct to identify a msg context
 * - the pair of message-id and pid (fields in sip_msg_t)
 */
typedef struct msg_ctx_id
{
	unsigned int msgid;
	int pid;
} msg_ctx_id_t;

/**
 * set msg context id
 * - return: -1 on error; 0 - on set
 */
int msg_ctx_id_set(const sip_msg_t *const msg, msg_ctx_id_t *const mid);

/**
 * check msg context id
 * - return: -1 on error; 0 - on no match; 1 - on match
 */
int msg_ctx_id_match(const sip_msg_t *const msg, const msg_ctx_id_t *const mid);

/**
 * set msg time value
 */
int msg_set_time(sip_msg_t *const msg);

/**
 * reset content of msg->ldv (msg_ldata_t structure)
 */
void msg_ldata_reset(sip_msg_t *);

/**
 * replace \r\n with . and space
 */
char *ksr_buf_oneline(char *inbuf, int inlen);

/**
 * get source ip, port and protocol in SIP URI format
 */
int get_src_uri(sip_msg_t *m, int tmode, str *uri);

/**
 * get source proto:ip:port (socket address format)
 */
int get_src_address_socket(sip_msg_t *m, str *ssock);

/**
 * get received-on-socket ip, port and protocol in SIP URI format
 */
int get_rcv_socket_uri(sip_msg_t *m, int tmode, str *uri, int atype);

#endif
